So I was trying to install my Pioneer AVIC-Z1 but I am having some trouble with the illumination wire. I was told I should connect the unit to the headlight switch... Anyone done this? I am not exactly sure how I am supposed to remove the headlight switch from the dash and splice a wire over from the headunit to the switch. I know I need a wire that will go from 0 to 12+ volts so that the unit will know when I turn on the headlights.

Would appreciate any help....

The ILL Wire should be in the stock radio harness.
I have installed radios in 99-04 and 2005/6 Mustangs.
It has always been in the stock radio wiring harness.
(The radio lights up when you turn your lights on.)

BTW: I have a 2004 Mustang.
On mine the ILL was Orange.